attackfish

Wait, the Wizarding World has any hope of functioning as a just society? that's news to me. They don't go in for due process at all. (sorry, that's just snark) Dumbledore didn't seem much worried about the actual law but about the possibility that the magic in the house itself might consider Bellatrix its owner. The Blacks don't strike me as a family that cares much about legalities. Dumbledore might have been worried that they cast some sort of spell on the house that determines the heir regardless of the law. My theory is that while such a thing was not the case, Dumbledore might not have known Walburga re-inherited Sirius and feared that such a spell was the reason he had.

Or it could all be a case of Did Not Do Research on Ms. Rowling's part. But even if it is, that doesn't mean I can't try to explain it.